Private lawyers for President Trump accused House Democrats Monday of acting like a "junior-varsity IRS" for demanding Trump's tax returns.

In a letter sent Monday to the Treasury and IRS, Trump attorney William Consovoy aggressively tried to undercut the legal argument made by House Ways and Means Chairman Richard Neal, D-Mass., in setting a new deadline next week for the Treasury to turn over Trump's tax information.

Consovoy argued that Neal’s request to review Trump’s returns could not be taken at face value, and that the motivation for the demand violates the First Amendment of the Constitution.

“Congress’s motives do matter under the Constitution,” Consovoy wrote.

He argued that the request was motivated by political retaliation instead of legitimate congressional oversight. He added that Neal’s request is based in a “radical view of unchecked congressional power."

Neal, in providing a basis for the tax information request, has said that he wants to ensure that the IRS is auditing Trump, as it has done with every president for decades. Trump’s tax returns have been a source of controversy since he broke with 40 years' worth of precedent in declining to release them.

The Democratic lawmaker renewed the deadline for Trump’s returns after Treasury Secretary Steven Mnuchin said last week that the department would miss the initial due date set by Neal. The Democrat now wants Trump’s tax information by the end of the day on April 23.

The Treasury Department says it is following the president’s request, through his personal attorneys, to check with the Justice Department before fully responding to Neal’s request. Consovoy’s Monday letter and his prior April 5 letter appear to set up Trump’s arguments for a protracted legal battle to fight the request.